1. Field of the Invention
The present invention relates to an apparatus and method of removing color noise of a digital image, and more particularly, to an apparatus and method of removing color noise of a digital image that can remove color noise occurring in a high frequency region of a digital image independent of a color interpolation method by determining the high frequency region in a bayer image output from an image sensor, determining whether the high frequency region is a region in which color noise is generated, and correcting the region having the color noise in an RGB image subject to color interpolation (or color demosaicking).
2. Description of the Related Art
In general, each pixel of an image sensor that is used, for example, in a digital camera uses a color filter and detects one color among red, green, and blue (RGB). The image sensor, therefore, outputs a bayer pattern image. In the image output from the image sensor, color values may be determined during color processing in addition to a color value of the color detected by each of the pixels. As such, the image processing by which color values of the respective pixels of the image output from the image sensor is called color interpolation or color demosaicking.
When the color interpolation is performed on the bayer pattern image, color noise may occur in a high frequency region, such as the contour of a subject and the boundary of a pattern. In general, an image processing algorithm for color interpolation has been developed to suppress color noise as much as possible in consideration of the generation of color noise. That is, the color interpolation algorithm includes not only color interpolation but also a scheme of suppressing the generation of color noise.
Therefore, when a new color interpolation scheme is used in order to improve the color interpolation, the color interpolation and color noise suppression according to the related art need to be performed in consideration of color noise suppression as well as color interpolation. Further, in order to improve the color noise suppression, the entire color interpolation algorithm needs to be newly developed.